An expression designed to call something to mind without mentioning it explicitly; and indirect or passing reference.
As the price of five dollars was reasonable, I decided to make the purchase without further thought.
Here's your answer.
The answer is using energy.
When one is sweating or panting, they are usually found doing some form of physical activity-or doing something social, but that is not the point. When doing physical activity, it requires energy and protein, so it's safe to say that when someone is sweating or panting, they have been or are doing something that is using up their energy.
I hope this helps.
